JP5817043B2 - Non-contact transfer pad - Google Patents

Description

  The present invention uses a robot arm in which a plate-like part (work) such as a glass substrate used in a semiconductor wafer, a liquid crystal device or the like is held on the carry-out pad by ejecting gas to the carry-out pad, and the carry-out pad is fixed. The present invention relates to a non-contact transport pad that is used when a plate-like component (work) is removed from a carry-out pad by placing the plate-like component (work) at a predetermined position and stopping gas ejection.

  In recent years, the consumption of liquid crystal panels and the like has been increasing, and the consumption of pads such as semiconductors is still persistent. In order to transport liquid crystal panels and semiconductor wafers, the liquid crystal panels and semiconductor wafers can be held cleanly, firmly and quickly without being scratched, damaged, moved by a robot, etc. It is necessary to place it. What is used at that time is a non-contact transfer pad that can be sucked and held.

  So far, non-contact transport pads are known as 1) non-contact transport pads by Bernoulli method and 2) non-contact transport pads by vortex method.

As a non-contact conveyance pad by the Bernoulli method, as shown in Patent Document 1, in a non-contact conveyance pad that lifts and conveys a workpiece in a non-contact manner using positive pressure, a radial flow generated between the workpiece and the non-contact conveyance pad A non-contact transfer pad that performs lifting transfer using the Bernoulli effect of the above is disclosed.
In particular, in FIG. 3, the pressure decreases as the flow rate increases with the restriction. When this theorem is applied to FIG. 2, a radial flow is generated in the gap between the workpiece and the non-contact transfer pad body. As this radial flow flows to the periphery, the flow velocity decreases and the pressure increases. Therefore, a negative pressure is generated toward the center. The closer to the center, the greater the negative pressure.

  Further, as a non-contact transport pad by a vortex method, as shown in Patent Document 2, a non-contact suction tool for holding a suction target object in a non-contact state, a cylindrical recess opening on a suction surface; A fluid channel for injecting fluid into the recess, and the width H of the fluid channel and the radius R of the recess are set to satisfy 0.1 ≦ H / R ≦ 0.5, The axis CL of the fluid flow path is provided so as to be orthogonal to the diameter line D of the recess, and the coordinate S with respect to the intersection P of the axis CL and the diameter line with the center O of the recess as the origin is 0. A non-contact adsorber set to satisfy .25R ≦ S ≦ 0.80R is disclosed.

In addition, as shown in Patent Document 3, a manually operated non-contact hand provided with a handle and a guide equipped with a gas supply valve on a non-contact suction tool that holds a work in a non-contact manner by ejecting gas. There is.
JP 2008-284671 A JP 2006-114748 A Japanese Patent Laid-Open No. 2005-251984

  The present invention is an improved invention of a non-contact transport pad by the Bernoulli method. The suction force is stronger than the conventional one, and the suction and non-suction operations are easy as in the prior art. It is an object of the present invention to provide a non-contact transfer pad that can be kept clean without scratching.

  Further, the present invention provides a non-contact transport pad that can be more strongly adsorbed by the conventional Bernoulli method and at the same time, reduces noise caused by the jet.

According to Bernoulli's theorem, the pressure decreases as the flow velocity increases.
By utilizing this principle, a higher negative pressure can be generated and a higher adsorption force can be obtained by increasing the flow velocity.
However, it has been found that there is a problem in the environment because the gas jet power can cause enormous noise in the surrounding area.

Therefore, the present invention provides a non-contact transport pad that can more strongly adsorb plate-like parts (workpieces) and at the same time reduce noise caused by jets.
That is, the present invention is a cylindrical non-contact transfer pad composed of an upper main body, a middle main body, and a lower main body, in which compressed gas is introduced into an introduction port at the center of the upper body of the transfer pad, and is obliquely removed from the introduction port. A flow path that leads to the flow path introduced into the flow path and continues to the lower body through the middle body is narrowed so that the cross-sectional area of the flow path decreases from the flow path of the lower body to the ejection hole. Is ejected in the outer peripheral direction from the ejection hole around the center part of the lower body, and the end surface of the outer peripheral part of the bottom surface of the transport pad is notched to an angle of 12 degrees or less over the entire circumference in the non-contact transport pad that sucks and holds the plate-like component Provided with a diffuser, and a second inlet for introducing a parallel flow slower than the second main flow from the outer periphery of any of the upper main body, the middle main body, and the lower main body, and a second flow path, Second The flow passage is narrowed from the passage to the second ejection hole so that the cross-sectional area of the passage becomes smaller, and the second ejection hole is formed on the outer peripheral portion of the lower main body, directly above the diffuser notched at an angle of 12 degrees or less. A non-contact transport pad is provided, wherein a parallel flow slower than the second main flow is ejected from the second ejection hole in the outer peripheral direction.

In the non-contact transport pad of the present invention, the distance d between the bottom surface of the lower body and the adsorbing plate-like component and the height Δh between the bottom surface of the lower body and the outer peripheral surface of the diffuser are substantially the same. The angle of the notched diffuser can be 8 degrees.
Furthermore, in the non-contact conveyance pad of this invention, the diffuser notched by the angle of 12 degrees or less can be provided in the end surface of the 2nd ejection hole.
Moreover, in the non-contact conveyance pad of this invention, an upper main body, a middle main body, and a lower main body can be fixed with a volt | bolt via an O-ring.
Furthermore, in the non-contact transport pad of the present invention, the upper body, the middle body, and the lower body can be integrally formed.

  Since the configuration as described above is adopted, according to the present invention, the adsorption force is increased by the diffuser effect and at the same time the noise due to the ejection of the fluid is remarkably reduced. Work efficiency can be improved by increasing power.

Cross-sectional view of a non-contact transfer pad with the same bottom surface as conventional products Sectional drawing of the non-contact conveyance pad by Example 1 of this invention Sectional drawing of the non-contact conveyance pad by Example 2 of this invention Implementation of Example 1 of the present invention Difference in adsorption force of non-contact transfer pad according to the first embodiment of the present invention Pressure distribution of non-contact transfer pad according to embodiment 2 of the present invention Noise characteristics of non-contact transfer pad according to Example 2 of the present invention (in the case of the same compressed air pressure) Noise characteristics of non-contact transfer pad according to Example 2 of the present invention (in the case of the same adsorption force)

  FIG. 1 shows a schematic view of a non-contact transport pad 1 according to the prior art, in which a compressed gas is ejected to adsorb a plate-like component (workpiece) 20. The compressed gas is introduced into the introduction port 2 at the center of the upper main body 11 of the cylindrical transport pad 1, led to the flow path 3 introduced obliquely outward from the introduction port 2, and the lower main body via the middle main body 12. 13 is formed, and the flow path 3 is narrowed in the vicinity of the flow path 4 from the lower body flow path 5 inlet to the ejection hole 6 so that the cross-sectional area of the flow path becomes small, and high-speed compressed gas is generated. It is ejected from the ejection hole 6 around the center of the lower body 13 in the outer circumferential direction.

The flow path 5 is made of a substantially smooth linear wall from the flow path 4 to the ejection hole 6, and its cross-sectional area is configured to be small from the flow path 5 to the ejection hole 6.

  The stud 8 may be integrally formed by injection molding, die-casting, casting, etc. with the same material as the transport pad 1, for example, synthetic resin, aluminum, alloy, etc., but is manufactured as a separate body and integrated with the bolt 10 or the like when assembled. You can assemble to become.

    In addition, the compressed gas inlet 2 may be provided at the upper center of the transport pad 1 as shown in FIG. 1, or provided laterally from the intermediate portion of the transport pad 1 as shown in FIG. Also good.

The gas ejected from the ejection holes 6 is led out in the outer peripheral direction of the transport pad 1 along the bottom surface of the transport pad 1 and the surface of the plate-like component (workpiece) 20.
At this time, the conveyance pad 1 can suck the plate-like component (work) 20 through the distance d and can hold the plate-like component (work) 20 with the non-contact conveyance pad.

In the present invention, as shown in FIG. 2, in the non-contact transport pad of the present invention, there is provided a diffuser in which the end surface of the bottom surface of the bottom body of the transport pad is cut out at an angle of 12 degrees or less over the entire circumference.
If the angle of the notched diffuser is set to 12 degrees or more, noise will increase and the attractive force will also decrease. Even if the angle of the cut-out diffuser is 1 degree, the effect is reduced, but it functions as a diffuser.
Furthermore, the distance d between the bottom surface of the lower body and the adsorbed plate-like component and the height Δh between the bottom surface of the lower body and the outer peripheral surface of the diffuser are substantially the same, and the angle of the notched diffuser is 8 Degree is desirable.
By providing the diffuser 14, the suction force of the transport pad 1 can be increased, and noise caused by the jet can be reduced.

Further, in the present invention, the non-contact transport pad of the present invention shown in FIG. 2 is further delayed from the outer peripheral portion of any one of the upper main body, the middle main body, and the lower main body, as shown in FIG. A second inlet 132 for introducing a parallel flow is provided, and the second channel 133 is narrowed from the second channel to the second ejection hole 136 so that the cross-sectional area of the channel becomes smaller. Is provided on the outer peripheral portion of the lower main body, directly above the diffuser 114 cut out at an angle of 12 degrees or less, and a parallel flow slower than the second main flow is directed outwardly from the second jet hole 136. It is possible to provide a non-contact transfer pad which is characterized by being ejected to the surface.
The flow velocity of the parallel flow slower than that of the second main flow is preferably about 30 to 70%, particularly about 45 to 55%, and most preferably 50% of the flow velocity of the main flow, and noise can be reduced.

By incorporating this configuration, it was further demonstrated that noise caused by the jet can be reduced.
Next, a specific example will be described.

An example of the non-contact transport pad 100 of the present invention is shown in FIG.
The upper body 11, the middle body 12, and the lower body 13 are composed of a cylindrical non-contact transfer pad 100 having a diameter of 40 mm. The middle body 12 hangs the stud support portion 7 from the central portion, and attaches the conical stud 8. The conical stud 8 is disposed in a substantially conical inner circumferential recess provided in the lower main body 13 of the transport pad so as to face the conical stud 8. Compressed gas is introduced into the introduction port 2 at the center of the upper body of the transport pad, led to the flow channel 3 introduced obliquely outward from the introduction port 2, and the flow channel continuing to the lower body 13 through the middle body 12. 3 is formed. The flow passage 3 is narrowed so that the cross-sectional area of the flow passage 3 decreases from the lower main body flow passage 4 to the ejection hole 6, and the compressed gas flows between the conical stud 8 supported by the stud support portion 7 and the bottom surface of the lower main body 13. Therefore, it is ejected as a high-speed compressed gas from the ejection hole 6 around the center of the lower main body 13 in the outer peripheral direction. A non-contact transfer pad for adsorbing and holding the plate-like component 20 was obtained by providing a diffuser 14 in which the end face of the bottom surface of the lower main body of the transfer pad was cut out at an angle of 8 degrees over the entire circumference.
In the present invention, four types of non-contact transport pads having the forms shown in the following table were prepared using the embodiment shown in FIG. 4 having different diameters d ′ of the studs 8 and various experiments were tried.

図４に示すように、圧縮気体を流すとベルヌーイの原理により、搬送パッドは板状部品（ワーク）を下部本体１３の底面の間の間隔ｄを保持して吸引する。供給する圧縮気体の圧力を変えると図５に示す結果を得た。


吸着装置の吸着面が壁面に近接している際の壁面圧力計測には、Scanivalve社製DSA3217/16Px-15psidを用い、壁面には0.5mmの圧力孔を中心より螺旋状に17か所設け、各孔より圧力分布を計測した。圧力センサーの性能は、最大差圧が約±100kPa、精度は±0.05kPaである。圧力孔は半径方向に2.5mm置き、回転方向に22.5度置きに設けられている。計測時には壁面を22.5度置きに一周回転させて壁面全体の圧力分布を取得し、圧力分布を面積で積分することで吸着力を算出した。
供給空気が吸着装置と壁面の間隙から大気に放出されるときの速度計測には、KANOMAX製熱線流速計システム7000に上流形熱線プローブMODEL1212を組み合わせ、トラバース装置により自動計測を行った。また熱線流速計の校正装置としてKANOMAX製プローブキャリブレータMODEL1065を用いて精度を確保した。

As shown in FIG. 4, when a compressed gas is flowed, the transport pad sucks the plate-like component (workpiece) while maintaining the distance d between the bottom surfaces of the lower body 13 according to the Bernoulli principle. When the pressure of the compressed gas to be supplied was changed, the result shown in FIG. 5 was obtained.


For wall pressure measurement when the adsorption surface of the adsorption device is close to the wall surface, DSA3217 / 16Px-15psid made by Scanivalve was used, and the wall surface was provided with 17 0.5mm pressure holes spirally from the center, The pressure distribution was measured from each hole. The pressure sensor has a maximum differential pressure of about ± 100 kPa and an accuracy of ± 0.05 kPa. The pressure holes are placed 2.5 mm in the radial direction and 22.5 degrees in the rotational direction. During measurement, the wall surface was rotated once every 22.5 degrees to obtain the pressure distribution of the entire wall surface, and the adsorption force was calculated by integrating the pressure distribution with the area.
For the velocity measurement when the supply air is released to the atmosphere through the gap between the adsorption device and the wall surface, the upstream hot wire probe MODEL1212 is combined with the KANOMAX hot wire anemometer system 7000, and automatic measurement is performed by the traverse device. In addition, KANOMAX probe calibrator MODEL1065 was used as a calibration device for hot-wire anemometers to ensure accuracy.

  FIG. 5 shows the difference in adsorption force depending on the diameter of the diffuser and the stud. FIG. 5 shows a comparison of wall surface average pressure distribution according to valve diameters of type 0 and type 1 when supply pressure Pr = 0.3 MPa. As shown in FIG. 5, the suction force is increased in Type 1 in which the end portion is processed into a diffuser shape as compared with Type 0d'09. This can be understood from FIG. 6 from the fact that the negative pressure region expands in the radial direction. However, the negative pressure near the center of the adsorption surface is small in type 1d'09 having the same valve diameter d = 9 mm as in type 0d'09 and type 0d'15 having a large valve diameter d = 15 mm. This indicates that there is an optimum size for the presence or absence of the diffuser and the valve diameter. In the range of this experimental condition, the negative pressure near the center of the adsorption surface is large in the case of type 0d'11 with the valve diameter d = 11 mm. Recognize.

Another embodiment of the present invention is shown in FIG.
It consists of a cylindrical non-contact transfer pad 101 composed of an upper body 111, a middle body 112, and a lower body 113. The middle body 112 supports a conical stud 108 by hanging a stud support 107 from the center. In addition, the conical stud 108 is disposed in a substantially conical inner circumferential recess provided in the lower body 113 of the transport pad. The compressed gas is introduced into the introduction port 102 at the center of the upper body of the transport pad, guided to the flow channel 103 introduced obliquely outward from the introduction port 102, and the flow channel 103 continuing to the lower body 113 through the middle body 112. Is formed so that the cross-sectional area of the flow path decreases from the lower main body flow path 104 to the ejection hole 106, and the compressed gas flows between the conical stud 108 supported by the stud support portion 107 and the lower main body 113. From the bottom surface, it is ejected as a high-speed compressed gas in the outer peripheral direction from the ejection hole 106 around the center of the lower body.
In the non-contact transfer pad 101 that sucks and holds the plate-like component 120, a diffuser 114 in which the end face of the bottom outer peripheral part of the transfer pad is notched in a taper shape at an angle of 8 degrees is provided over the entire periphery. A second introduction port 132 for introducing a parallel flow slower than the second main flow is provided from the outer peripheral portion of either the main body 112 or the lower main body 113, and the second flow path 133 and the second flow path 133 are connected to the second flow path 133. The second jet hole 136 is narrowed so as to reduce the cross-sectional area of the flow path over the second jet hole 136, and the second jet hole 136 is located on the outer peripheral portion of the lower body, directly above the diffuser 114 that is tapered at an angle of 8 degrees. A non-contact transport pad, wherein a parallel flow slower than the second main flow is ejected from the second ejection hole 136 in the outer peripheral direction. 112, the lower body 113, via the O-ring was prepared by bolted.

The improvement of the pad takes two types of measures as shown in FIG. First, a diffuser is installed to moderate the velocity gradient near the exit (type 1). The diffuser had an angle of 8 degrees and a distance of 2.5 mm. In addition, a parallel flow jet (type 2) that is slower than the main flow to relieve the shear layer gradient at the jet will be added. In addition, a type 3 type in which a diffuser having an angle of 8 degrees and a distance of 2.5 mm is also provided at a parallel flow outlet 136 (above 114) that is slower than the main flow can be produced.
The noise reduction experiment of the suction pad is conducted in a semi-anechoic chamber, and the noise is evaluated at six 60 degree intervals (70cm distance from the pad, 45 degree angle) so that the B & K 1 / 2-inch microphone surrounds the transfer pad. . The microphone output is simultaneously sampled. The supply pressure produced by the compressor is stored in two pressure tanks with a capacity of 230L (for main flow and for parallel flow slower than the main flow) so that the pressure can be kept constant even during long-term measurement.
It can be seen that the noise and suction force of the Bernoulli type suction pad of type 0d'09 used in Example 1 increases as the supply pressure is increased. In the type 1d'09 of the first embodiment with the diffuser, the amount of noise is also reduced because the jet velocity at the outlet is reduced. In addition, since the flow resistance is reduced and the flow velocity of the gap is increased by attaching the diffuser, the attractive force is increased. Next, in the case of Type 2 in which a parallel flow slower than the main flow having an intermediate velocity is added between the jet and the atmosphere (speed 0), the noise pressure is not as good as that of the diffuser, but the sound pressure around the entire circumference decreases. I found out. Furthermore, it was found that the sound pressure was further reduced in Type 3, which had a diffuser (angled) at a parallel outlet that was slower than the main stream, although the adsorption force was slightly reduced. This is considered to be because the step at the exit has been eliminated.

When considering the diameter of the stud from the standpoint of the attractive force, the performance of d '= 11 mm (Example 1 type d'11) is good, and the attractive force is twice that of Type 0 (Example 1 type 0d'09). It has become.
When the stud diameter is 9 mm, the noise amounts of Type 1 (Example 1 type 1d'09) and Type 2 (Example 2 type 2) are summarized in FIG.
It has been found that type 1 and type 2 have much lower noise than type 0.
Furthermore, type 0 (compressed gas supply pressure 0.5Mpa), type 1 (compressed gas supply pressure 0.3Mpa), type 3 (compressed gas supply pressure 0.3Mpa) when the suction force is constant (about 10N) The result of examining the noise of the pad is shown in FIG.
It has been found that Type 1 and Type 3 can lower the supply pressure of the compressed gas and have lower noise than Type 0.

Further, at the compressed gas supply pressure Pr = 0.3 Mpa, the type 1d′11 with a diffuser reduces the sound from −3.8 dB to −10.6 dB. The type 2d′11 with the secondary flow nozzle opened has a sound reduction effect of −4.2 dB to −11 dB. Further, in the case of the type 3d'11 in which the nozzle of the parallel flow slower than the main flow is opened as a double diffuser, the noise was reduced from -7.8 dB to -9.1 dB. It was confirmed that the noise around the entire area was reduced by the diffuser, and by parallel flow slower than the mainstream.
According to the result of the analysis of the microphone pressure at the supply pressure Pr = 0.3Mpa and 90 degrees, the sound reduction effect cannot be confirmed up to 1kHz for each type, but the sound is reduced in the range of 2kHz to 7kHz in Type 1. Furthermore, in Type 3, the sound reduction in the frequency band of 8 kHz or more is more prominent, and it can be seen that the speed decrease and the speed gradient are alleviated by the diffuser and the parallel flow slower than the main flow. The effect of parallel flow slower than the diffuser and main flow is similar to other supply pressures.

  Since the non-contact transport pad of the present invention can be transported in a non-contact manner, it is suitable for transporting medical products, food products, and the like.

DESCRIPTION OF SYMBOLS 1 Transfer pad 2 Compressed gas inlet 3 Flow path 4 Flow path 5 Lower main body flow path 6 Jetting hole 7 Stud support part 8 Stud 9 O-ring 10 Bolt 11 Upper main body 12 Middle main body 13 Lower main body 20 Plate-shaped component (work)
DESCRIPTION OF SYMBOLS 100 Transfer pad 14 Diffuser 101 Transfer pad 102 Compressed gas introduction port 103 Flow path 104 Flow path inlet 105 Lower main body flow path 106 Outlet hole 107 Stud support part 108 Stud 109 O-ring 110 Bolt 111 Upper main body 112 Middle main body 113 Lower main body 114 Diffuser 120 Plate-shaped part (work)
132 Second inlet 133 Second flow path 136 Second ejection hole

Claims (5)

A cylindrical non-contact transfer pad composed of an upper main body, a middle main body, and a lower main body, in which compressed gas is introduced into the introduction port at the center of the upper main body of the transfer pad and is introduced obliquely outward from the introduction port. A flow path following the lower main body is formed through the middle main body, narrowed so that the cross-sectional area of the flow path decreases from the lower main body flow path to the ejection hole, and high-speed compressed gas is fed to the central portion of the lower main body. In the non-contact transport pad that is ejected from the peripheral ejection holes in the outer peripheral direction and sucks and holds the plate-like component, a diffuser is provided in which the end surface of the bottom outer peripheral portion of the transport pad is cut out at an angle of 12 degrees or less over the entire circumference. Furthermore, a second introduction port for introducing a parallel flow slower than the second main flow is provided from the outer peripheral portion of any one of the upper main body, the middle main body, and the lower main body, from the second flow path and the second flow path. Second eruption From the second mainstream, by narrowing the flow passage so that the cross-sectional area of the flow passage becomes smaller, and providing the second ejection hole on the outer peripheral portion of the lower main body, directly above the diffuser notched at an angle of 12 degrees or less. A non-contact transport pad, wherein a slow parallel flow is ejected from the second ejection hole in the outer peripheral direction. The distance d between the bottom surface of the lower body and the adsorbed plate-like component and the height Δh between the bottom surface of the lower body and the outer peripheral surface of the diffuser are substantially the same, and the angle of the notched diffuser is 8 degrees. The non-contact transport pad according to claim 1. The non-contact transport pad according to claim 1, wherein a diffuser notched at an angle of 12 degrees or less is provided on an end face of the second ejection hole. The non-contact transport pad according to any one of claims 1 to 3 , wherein the upper main body, the middle main body, and the lower main body are fixed with bolts via an O-ring. The non-contact transport pad according to any one of claims 1 to 4 , wherein the upper body, the middle body, and the lower body are integrally molded.

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